Oracle SQL - can CASE be used in a check constraint to determine data attributes?

Question

I\'m using Oracle 10g and I want to apply a constraint to a table where the value entered for one column determines whether another column IS NULL or IS NOT NULL. Column1 ca

Answer 1

Since CASE expressions must return a value, and check constraints are boolean, you'll have to compare the result with something, e.g.:

CONSTRAINT ck_1 CHECK (CASE WHEN col2 IS NOT NULL THEN 1 ELSE 0 END = col1);